The camera module consists of a light-sensitive chip and an imaging lens group, wherein the imaging lens group is disposed in the lens cone of the module and only an active coordination of positions of the lens cone and the light-sensitive chip can obtain a high-quality image or video. As for the modern handheld device, on one hand, it is designed to be thinner and thinner for aesthetic needs, and the height of the camera module becomes lower and lower, and correspondingly the total height of the lens group is reduced; on the other hand, in order to meet the demand of image quality, diagonal dimension of the light-sensitive surface of the light-sensitive chip is growing. Therefore, it is always a problem in the handheld device design industry how to ensure keeping the viewing angle of the lens group constant, increasing the light-sensitive chip size, and meeting the appearance design requirement of the handheld device of a thinner body. The digital camera, especially the ultra-thin digital camera employs a stretchable lens group to solve this problem, for example, a mechanical transmission structure such as a thread/nut structure, a gear structure, or a turbine vortex stem, but such a structure is relatively large and cannot be placed in a thinner device such as a mobile phone, a laptop, a Pad, etc. Regarding the voice coil motor commonly used in the existing thin and light devices, its lens cone cannot stretch out the camera module, and can only be used for automatic focusing; since it cannot realize the stretching function of the lens group at work, it cannot solve the problem caused by the height of the camera module becoming lower and lower. In addition, as for the existing camera module, in order to keep the lens cone in a certain position, it is necessary to continuously apply current to the coil to balance the elasticity of an elastomer, and thus the power consumption of the module is relatively large, and when the lens cone makes linear motions along the optical axis direction, since the optical axis direction lacks a guide structure, it is easy to shake and cause eccentricity of the optical path, thereby affecting the image quality.
Apparently, a thin and light electronic device needs a new kind of miniature camera module to solve the above contradiction between thickness and image quality of the existing module, and solve the problems in the existing module. Such a new kind of camera module can stretch the lens cone out of the module and ensure increasing the size of the light-sensitive chip on the condition of a constant viewing angle to improve the image quality, and meanwhile it is required that the structure is simple and can be applied to the thin and light electronic device such as a mobile phone, a pad, etc.